Implement configuration-based mod management and fix navigation spacing

## Major Features Added

### Configuration-Based Mod Management
- Implement proper Luanti mod system using load_mod_* entries in world.mt
- Add mod enable/disable via configuration instead of file copying
- Support both global mods (config-enabled) and world mods (physically installed)
- Clear UI distinction with badges: "Global (Enabled)", "World Copy", "Missing"
- Automatic registry verification to sync database with filesystem state

### Game ID Alias System
- Fix minetest_game/minetest technical debt with proper alias mapping
- Map minetest_game → minetest for world.mt files (matches Luanti internal behavior)
- Reference: https://github.com/luanti-org/luanti/blob/c9d4c33174c87ede1f49c5fe5e8e49a784798eb6/src/content/subgames.cpp#L21

### Navigation Improvements
- Fix navigation menu spacing and text overflow issues
- Change "Configuration" to "Config" for better fit
- Implement responsive font sizing with clamp() for better scaling
- Even distribution of nav buttons across full width

### Package Registry Enhancements
- Add verifyAndCleanRegistry() to automatically remove stale package entries
- Periodic verification (every 5 minutes) to keep registry in sync with filesystem
- Fix "already installed" errors for manually deleted packages
- Integration across dashboard, ContentDB, and installation workflows

## Technical Improvements

### Mod System Architecture
- Enhanced ConfigParser to handle load_mod_* entries in world.mt files
- Support for both configuration-based and file-based mod installations
- Proper mod type detection and management workflows
- Updated world details to show comprehensive mod information

### UI/UX Enhancements
- Responsive navigation with proper text scaling
- Improved mod management interface with clear action buttons
- Better visual hierarchy and status indicators
- Enhanced error handling and user feedback

### Code Quality
- Clean up gitignore to properly exclude runtime files
- Add package-lock.json for consistent dependency management
- Remove excess runtime database and log files
- Add .claude/ directory to gitignore

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.gitignore

@@ -50,6 +50,9 @@ Thumbs.db
 *.swo
 *~
 
+# Claude Code specific files
+.claude/
+
 # Temporary files
 tmp/
 temp/
@@ -75,8 +78,8 @@ backups/
 *.crt
 *.csr
 
-# Lock files
-package-lock.json
+# Lock files (keep package-lock.json for consistent installs)
+# package-lock.json
 yarn.lock
 
 # Coverage directory used by tools like istanbul